相位衬度成像及其计算层析(CT)技术不同于传统的吸收衬度成像，是一种新型的X射线成像技术，因具有高灵敏度、高衬度分辨率、能对软组织成像等特点而受到广泛关注。鉴于相位衬度CT往往导致非常长的辐射时间和巨大的辐射剂量，而稀疏角度重建在降低辐射剂量方面又有着非常明显的优势，因此，研究针对相位衬度CT的稀疏角度重建算法就变得非常有意义。近年来，针对解决稀疏重建的Bregman算法在图像处理方面被广泛应用。将Bregman分离执行(BOS)算法引入到微分相位衬度CT中，提出了一种稀疏角度相位衬度CT的交替迭代重建算法。数值模拟和实验表明，该方法可以在少量的投影数据下获得较好的重建效果。

Phase-contrast computed tomography (CT), different from traditional absorption-contrast tomography, is a novel X-ray inspection method and has been widely used for it′s high sensitivity, high resolution and better reconstructions for soft tissues. However, phase-contrat CT usually leads to unacceptably long exposure time and huge X-ray doses. Sparse angular algorithms show significant advantage over in reducing the X-ray doses. Thus, the study of sparse angular differential phase-contrast CT (DPC-CT) is particularly meaningful. After analyzing the characteristics of the DPC-CT, the Bregman operator splitting (BOS) algorithm is introduced into DPC-CT reconstruction and an alternating iteration algorithm for sparse angular DPC-CT is proposed. The numerical simulation and experiment results show that the proposed algorithm can obtain higher reconstruction quality in sparse angular condition.